The processing of whole birds such as chickens, turkeys, etc., through poultry processing plants now has become highly automated. In general, the birds are suspended from overhead conveyor lines and carried by their legs through a series of processing stations where the birds are killed, defeathered, eviscerated and cut-up. For example, the live birds generally are hung on a killing line where they are stunned, killed, scalded and defeathered at automated processing stations along the processing path of the birds before passing to evisceration and cut-up lines for further processing. As the birds are moved along the evisceration line, the birds also are inspected for contamination.
If contamination of any of the birds is detected during the inspection, the contaminated birds must be removed from the main processing line and sent through a reprocessing operation during which the birds typically are cleaned with a solution, such as a chlorine and water solution, and are scrubbed and then inspected again before the birds are allowed to proceed for cut-up and final processing. Such reprocessing increases the time and expense of preparing the birds for the market and reduces the production capacity of the processing line, and if contamination still is detected after reprocessing, the birds must be discarded.
Typically, the birds arrive at the processing plant in a unsanitary, dirty condition, with fecal matter and other contaminants on their feathers. Further, the lower digestive tracts of the birds often are filled with fecal matter that may not be fully evacuated or excreted from the vents of the birds before the birds are processed.
During initial processing, the birds are stunned and killed, after which the birds are passed through a scalder, which typically is a long tank or bath where the birds are immersed in water that is at a temperature of approximately 125.degree.-140.degree.. The purpose of the scalder is to loosen the feather follicles of the birds so that the feathers can be removed by the defeathering machine. The scalder also tends to wash the birds and clean the birds of surface dirt. However, as a result of the handling of the birds as they are stunned, killed, etc., the birds tend to excrete fecal matter, some of which contaminates the feathers of the birds. The birds therefore are exposed to and tend to pickup bacteria and further contamination as they are moved along the killing line.
Spray scalders are also in use, and instead of immersing the birds in heated water, tend to spray the birds with high temperature water to cause the feather follicles to loosen. Such spray scalders generally do not, however, adequately wash and clean the birds of surface contaminants prior to the birds entering the pickers where the feathers of the birds are removed. In addition, the spray scalders do not clean the birds of any material contaminants contained within the digestive tracts of the birds, which contaminants instead tend to remain in and possibly become expelled from the birds as the birds are eviscerated.
Conventional evisceration equipment often is equipped with vacuum means designed to draw off fecal matter and other contaminants from within the visceral cavities of the birds as the birds are eviscerated. The problem with such vacuum systems, however, is that the eviscerating probes tend to limit the action of the vacuums and thus prevent the vacuums from fully evacuating the visceral cavities of the birds of contaminating matter. Thus, the entrails of the birds, which are laid over the birds after evisceration for inspection, sometimes are coated with contaminants such as fecal matter that has not been completely washed away by the sprayers positioned along the evisceration line. If contaminating matter is detected on the entrails, the inspector must reject the birds and the birds must go to reprocessing.
It is estimated that the loss in production of birds in conventional processing plants due to the reprocessing of contaminated birds averages about 3 to 4 percent of the production of the line, which translates to roughly 4 to 5 birds per minute or up to as many as 2,000 birds per day that must be reprocessed or discarded. Thus, it is important for the birds to be as clean as possible before proceeding through evisceration and cut-up to reduce the amount of contamination and thus reduce the number of birds that must be reprocessed.
Accordingly, it can be seen that a need exists for a method and apparatus for processing birds wherein the birds are cleaned of contaminating material on the bodies of the birds and within the intestinal tracts of the birds prior to defeathering the birds so that the birds are substantially cleaned prior to evisceration and inspection, to reduce the amount of loss in production.